Citation and License

Nutrition Journal 2012, 11:16
doi:10.1186/1475-2891-11-16

Published: 21 March 2012

Abstract

Background

We have recently reported that short-term (21-day) dietary modification in accordance
with a stringent vegan diet (i.e., a Daniel Fast) lowers blood lipids as well as biomarkers
of oxidative stress. However, this work only involved measurements obtained in a fasted
state. In the present study, we determined the postprandial response to a high-fat
milkshake with regards to blood triglycerides (TAG), biomarkers of oxidative stress,
and hemodynamic variables before and following a 21-day Daniel Fast.

Methods

Twenty-two subjects (10 men and 12 women; aged 35 ± 3 years) completed a 21-day Daniel
Fast. To induce oxidative stress, a milkshake (fat = 0.8 g·kg-1; carbohydrate = 1.0 g·kg-1; protein = 0.25 g·kg-1) was consumed by subjects on day one and day 22 in a rested and 12-hour fasted state.
Before and at 2 and 4 h after consumption of the milkshake, heart rate (HR) and blood
pressure were measured. Blood samples were also collected at these times and analyzed
for TAG, malondialdehyde (MDA), hydrogen peroxide (H2O2), advanced oxidation protein products (AOPP), nitrate/nitrite (NOx), and Trolox Equivalent
Antioxidant Capacity (TEAC).

Results

A time effect was noted for HR (p = 0.006), with values higher at 2 hr post intake of the milkshake as compared to pre
intake (p < 0.05). Diastolic blood pressure was lower post fast as compared to pre fast (p = 0.02), and a trend for lower systolic blood pressure was noted (p = 0.07). Time effects were noted for TAG (p = 0.001), MDA (p < 0.0001), H2O2 (p < 0.0001), AOPP (p < 0.0001), and TEAC (p < 0.0001); all concentrations were higher at 2 h and 4 h post intake compared to pre
intake, except for TEAC, which was lower at these times (p < 0.05). A condition effect was noted for NOx (p = 0.02), which was higher post fast as compared to pre fast. No pre/post fast × time
interactions were noted (p > 0.05), with the area under the curve from pre to post fast reduced only slightly
for TAG (11%), MDA (11%), H2O2 (8%), and AOPP (12%), with a 37% increase noted for NOx.

Conclusion

Partaking in a 21-day Daniel Fast does not result in a statistically significant reduction
in postprandial oxidative stress. It is possible that a longer time course of adherence
to the Daniel Fast eating plan may be needed to observe significant findings.